Prepare v0.12.0b5 release

Author: kbattocchi

README.md

@@ -45,10 +45,12 @@ For information on use cases and background material on causal inference and het
 
 # News
 
-**July 9, 2021:** Release v0.12.0b4, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.12.0b4)
+**August 3, 2021:** Release v0.12.0b5, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.12.0b5)
 
 <details><summary>Previous releases</summary>
 
+**July 9, 2021:** Release v0.12.0b4, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.12.0b4)
+
 **June 25, 2021:** Release v0.12.0b3, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.12.0b3)
 
 **June 18, 2021:** Release v0.12.0b2, see release notes [here](https://github.com/Microsoft/EconML/releases/tag/v0.12.0b2)

econml/__init__.py

@@ -26,4 +26,4 @@
            'dowhy',
            '__version__']
 
-__version__ = '0.12.0b4'
+__version__ = '0.12.0b5'